# US 11,114,862 B2 · Localized power point optimizer for solar cell installations > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,114,862 B2 - Document ID: US11114862B2 - Status: Granted - Kind: B2 - Application number: 16/056,084 - Filed: 2018-08-06 - Published: 2019-02-14 - Granted: 2021-09-07 - Earliest claimed: 2007-03-30 - Assignees: Enphase Energy, Inc. - Applicants: Enphase Energy, Inc. - Inventors: David L. Klein; Jan Mark Noworolski - Web page: https://patentgrep.com/patent/US11114862B2 ## CPC - H02S 50/10: Testing of PV devices, e.g. of PV modules or single PV cells (testing of semiconductor devices during manufacturing {H10P74/00}) - H02J 3/38: Arrangements for feeding a single network from two or more generators or sources in parallel; Arrangements for feeding already energised networks from additional generators or sources in parallel - H02J 3/381: {Dispersed generators} - H02J 3/46: Controlling the sharing of generated power between the generators, sources or networks - H02M 3/155: using semiconductor devices only - H02S 40/36: characterised by special electrical interconnection means between two or more PV modules, e.g. electrical module-to-module connection - H02S 50/00: Monitoring or testing of PV systems, e.g. load balancing or fault identification - H10F 77/955: {for photovoltaic devices} - H02J 2101/25: {involving maximum power point tracking control for photovoltaic sources} - H02M 1/0077: {Plural converter units whose outputs are connected in series} - Y02E 10/50: Photovoltaic [PV] energy - Y02E 10/56: Power conversion systems, e.g. maximum power point trackers - H02S: GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES (obtaining electrical energy from radioactive sources G21H1/12; light sensitive inorganic semiconductor devices H10F; light sensitive organic semiconductor devices H10K30/00; thermoelectric devices H10N10/00; pyroelectric devices H10N15/00) - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract In one embodiment, a solar cell installation includes several groups of solar cells. Each group of solar cells has a local power point optimizer configured to control power generation of the group. The local power point optimizer may be configured to determine an optimum operating condition for a corresponding group of solar cells. The local power point optimizer may adjust the operating condition of the group to the optimum operating condition by modulating a transistor, such as by pulse width modulation, to electrically connect and disconnect the group from the installation. The local power point optimizer may be used in conjunction with a global maximum power point tracking module. ## Claims ### Claim 1 A solar cell installation coupled to a load, the solar cell installation comprising: a first group of serially-connected solar cells having a first positive terminal and a first negative terminal; a first local power point optimizer coupled to the first positive terminal and the first negative terminal, the first local power point optimizer including: (a) a first transistor coupled to the first positive terminal, (b) a power point controller configured to control a voltage of the first group of serially-connected solar cells by modulating the first transistor to electrically connect and disconnect the first group of serially-connected solar cells, and (c) an output stage configured to alter a voltage output of the first local power point optimizer; a maximum power point tracking module configured to adjust an operating point of the first group of serially-connected solar cells to maximize the overall output power to the load as determined by the maximum power tracking module; and a second group of serially-connected solar cells having a second positive terminal and a second negative terminal; and a second local power point optimizer coupled to the second positive terminal and the second negative terminal, the second local power point optimizer including: (a) a second transistor coupled to the second positive terminal, (b) a power point controller configured to control a voltage of the second group of serially-connected solar cells by modulating the second transistor to electrically connect and disconnect the second group of serially-connected solar cells, and (c) an output stage configured to alter a voltage output of the second local power point optimizer; wherein the first group of serially-connected solar cells and the first local power point optimizer and the second group of serially-connected solar cells and the second local power point optimizer are connected in electrical series, wherein the maximum power point tracking module is further configured to adjust an operating point of the second group of serially-connected solar cells to maximize the overall output power to the load as determined by the maximum power tracking module. ### Claim 2 (depends on 1) The solar cell installation of claim 1 further comprising: a third group of serially-connected solar cells having a third positive terminal and a third negative terminal; and a third local power point optimizer coupled to the third positive terminal and the third negative terminal, the third local power point optimizer including: (a) a third transistor coupled to the third positive terminal, (b) a power point controller configured to control a voltage of the third group of serially-connected solar cells by modulating the third transistor to electrically connect and disconnect the third group of serially-connected solar cells, and (c) an output stage configured to alter a voltage output of the third local power point optimizer; wherein the first group of serially-connected solar cells and the first local power point optimizer, the second group of serially-connected solar cells and the second local power point optimizer, and the third group of serially-connected solar cells and the third local power point optimizer are connected in electrical series; and wherein the maximum power point tracking module is further configured to adjust an operating point of the third group of serially-connected solar cells to maximize the overall output power to the load as determined by the maximum power tracking module. ### Claim 3 (depends on 2) The solar cell installation of claim 2 wherein the first group of serially-connected solar cells and the first local power point optimizer, the second group of serially-connected solar cells and the second local power point optimizer, and the third group of serially-connected solar cells and the third local power point optimizer are included in a solar module. ### Claim 4 (depends on 1) The solar cell installation of claim 1 wherein the first local power point optimizer further includes a second transistor coupled to the first negative terminal, the second transistor providing a current path bypassing the first group of serially-connected solar cells when the first transistor is switched OFF. ### Claim 5 (depends on 4) The solar cell installation of claim 4 wherein the first transistor comprises a PFET and the second transistor comprises and NFET. ### Claim 6 (depends on 5) The solar cell installation of claim 5 wherein the output stage of the first local power point optimizer comprises: (i) an inductor having a first terminal and a second terminal and (ii) a capacitor having a first terminal and a second terminal, the first terminal of the inductor being coupled to the first transistor, the second terminal of the inductor being coupled to the first terminal of the capacitor, the second terminal of the capacitor being coupled to the first negative terminal. ### Claim 7 (depends on 1) The solar cell installation of claim 1 wherein the first transistor comprises a PFET. ### Claim 8 (depends on 1) The solar cell installation of claim 1 wherein the first transistor comprises an NFET. ### Claim 9 (depends on 1) The solar cell installation of claim 1 further comprising a voltage source configured to provide additional voltage to a gate of the first transistor to allow the first transistor to be switched ON. ### Claim 10 (depends on 1) The solar cell installation of claim 1 further comprising a diode across the first positive terminal and the second positive terminal wherein the diode is reversed biased during normal operation of the first group of serially-connected solar cells. ### Claim 11 (depends on 10) The solar cell installation of claim 10 wherein the diode is forward biased when the first group of serially-connected solar cells reverse polarity. ### Claim 12 (depends on 1) The solar cell installation of claim 1 further comprising a capacitor adapted to be charged by the first group of serially-connected solar cells when the first transistor is switched OFF. ### Claim 13 (depends on 12) The solar cell installation of claim 12 wherein the capacitor is adapted to discharge when a power generated by the first group of serially-connected solar cells is less than a power requested by the maximum power point tracking module. ### Claim 14 (depends on 1) The solar cell installation of claim 1 wherein the output stage of the first local power point optimizer is adapted to alter a voltage output of the first local power point optimizer by filtering the voltage output of the first local power point optimizer so the voltage output of the first local power point optimizer is steady over time. ### Claim 15 (depends on 1) The solar cell installation of claim 1 wherein the output stage of the first local power point optimizer further includes a sensing circuit adapted determine a current output of the first group of serially-connected solar cells and the voltage output of the first group of serially connected solar cells. ### Claim 16 A solar cell installation coupled to a load the solar cell installation comprising: a first solar module including: (a) a first group of serially-connected solar cells having a first positive terminal and a first negative terminal, (b) a first local power point optimizer coupled to the first positive terminal and the first negative terminal, the first local power point optimizer including: (i) a first transistor coupled to the first positive terminal, (ii) a power point controller configured to control a voltage of the first group of serially-connected solar cells by modulating the first transistor to electrically connect and disconnect the first group of serially-connected solar cells, and (iii) an output stage configured to alter a voltage output of the first local power point optimizer, (c) a second group of serially-connected solar cells having a second positive terminal and a second negative terminal, (d) a second local power point optimizer coupled to the second positive terminal and the second negative terminal, the second local power point optimizer including: (i) a second transistor coupled to the second positive terminal, (ii) a power point controller configured to control a voltage of the second group of serially-connected solar cells by modulating the second transistor to electrically connect and disconnect the second group of serially-connected solar cells, and (iii) an output stage configured to alter a voltage output of the second local power point optimizer, (e) a third group of serially-connected solar cells having a third positive terminal and a third negative terminal, and (f) a third local power point optimizer coupled to the third positive terminal and the third negative terminal, the third local power point optimizer including: (i) a third transistor coupled to the third positive terminal, (ii) a power point controller configured to control a voltage of the third group of serially-connected solar cells by modulating the third transistor to electrically connect and disconnect the third group of serially-connected solar cells, and (iii) an output stage configured to alter a voltage output of the third local power point optimizer, wherein the first group of serially-connected solar cells and the first local power point optimizer, the second group of serially-connected solar cells and the second local power point optimizer, and the third group of serially-connected solar cells and the third local power point optimizer are connected in electrical series; and a maximum power point tracking module configured to adjust an operating point of the first group of serially-connected solar cells of the first solar module, the second group of serially-connected solar cells of the first solar module, and the third group of serially-connected solar cells of the first solar module to maximize the overall output power to the load as determined by the maximum power tracking module. ### Claim 17 (depends on 16) The solar cell installation of claim 16 wherein the first local power point optimizer further includes a fourth transistor coupled to the first negative terminal, the fourth transistor providing a current path through the first group of serially-connected solar cells when the first transistor is switched OFF. ### Claim 18 (depends on 16) The solar cell installation of claim 16 further comprising: a second solar module including: (a) a first group of serially-connected solar cells having a first positive terminal and a first negative terminal, (b) a first local power point optimizer coupled to the first positive terminal and the first negative terminal, the first local power point optimizer including: (i) a first transistor coupled to the first positive terminal, (ii) a power point controller configured to control a voltage of the first group of serially-connected solar cells by modulating the first transistor to electrically connect and disconnect the first group of serially-connected solar cells, and (iii) an output stage configured to alter a voltage output of the first local power point optimizer, (c) a second group of serially-connected solar cells having a second positive terminal and a second negative terminal, (d) a second local power point optimizer coupled to the second positive terminal and the second negative terminal, the second local power point optimizer including: (i) a second transistor coupled to the second positive terminal, (ii) a power point controller configured to control a voltage of the second group of serially-connected solar cells by modulating the second transistor to electrically connect and disconnect the second group of serially-connected solar cells, and (iii) an output stage configured to alter a voltage output of the second local power point optimizer, (e) a third group of serially-connected solar cells having a third positive terminal and a third negative terminal, and (f) a third local power point optimizer coupled to the third positive terminal and the third negative terminal, the third local power point optimizer including: (i) a third transistor coupled to the third positive terminal, (ii) power point controller configured to control a voltage of the third group of serially-connected solar cells by modulating the third transistor to electrically connect and disconnect the third group of serially-connected solar cells, and (iii) an output stage configured to alter a voltage output of he third local power point optimizer, wherein the first group of serially-connected solar cells and the first local power point optimizer, the second group of serially-connected solar cells and the second local power point optimizer, and the third group of serially-connected solar cells and the third local power point optimizer are connected in electrical series; and wherein the maximum power point tracking module is further configured to adjust an operating point of the first group of serially-connected solar cells of the second solar module, the second group of serially-connected solar cells of the second solar module, and the third group of serially-connected solar cells of the second solar module to maximize the overall output power to the load as determined by the maximum power tracking module. ### Claim 19 (depends on 18) The solar cell installation of claim 18 wherein the first solar module, the second solar module, and the maximum power point tracking module are connected in electrical series. ### Claim 20 A solar cell installation coupled to a load, the solar cell installation comprising: a first group of serially-connected solar cells having a first positive terminal and a first negative terminal; a first local power point optimizer coupled to the first positive terminal and the first negative terminal, the first local power point optimizer including: (a) a first transistor coupled to the first positive terminal, (b) a power point controller configured to control a voltage of the first group of serially-connected solar cells by modulating the first transistor to electrically connect and disconnect the first group of serially-connected solar cells, and (c) an output stage configured to alter a voltage output of the first local power point optimizer; and a maximum power point tracking module configured to adjust an operating point of the first group of serially-connected solar cells to maximize the overall output power to the load as determined by the maximum power tracking module, wherein the output stage of the first local power point optimizer includes a sensing circuit adapted determine a current output of the first group of serially-connected solar cells and the voltage output of the first group of serially connected solar cells.